1. Field
Example embodiments relate to semiconductor devices and/or methods of manufacturing the semiconductor devices.
2. Description of the Related Art
A power device for controlling the flow of electric current through ON/OFF switching is required for various power conversion systems. In the power conversion systems, the efficiency of the power device may influence the efficiency of the entire system.
Examples of currently commercialized power devices include metal-oxide-semiconductor field-effect transistors (MOSFETs) and insulated gate bipolar transistors (IGBTs). It is typically difficult to increase the efficiency of a silicon-based power device due to limitations on the physical properties of silicon and limitations on the manufacturing process.
Recently, attempts to apply a compound semiconductor of III-V group to a power device have been made to increase conversion efficiency. In this regard, a high electron mobility transistor (HEMT) using a heterojunction structure of the compound semiconductor is receiving attention because the HEMT includes semiconductor layers having different electrical polarization characteristics. A semiconductor layer having relatively large polarizability from among the semiconductor layers may induce a 2-dimensional electron gas layer in another semiconductor layer joined thereto, and the 2-dimensional electron gas layer may have very high electron mobility.